The present invention is directed generally to a series of fins arranged within a brake drum for cooling, drying and cleaning the drum in response to rotation of the drum. The invention is particularly directed to fins for cleaning the brake drums of heavy-duty trucks on every r.p.m.
Approximately eighty percent of the accidents involving the big 18-wheel tractor-trailer trucks are caused by wet brakes. To dry their brakes, truckers can power brake (drive with the left foot on the brake pedal) but this results in significant wear of the brake shoes and drums. Mechanical shields have been proposed to keep the brakes dry but these cut off air circulation and make the brakes and wheel bearings run much hotter. Custom brake drums have been proposed including means for directing air exteriorly into the space between the wheel and brake drum but these are positioned radially away from the braking surfaces and operate to attract moisture along with the air.
Truckers going down a mountain put the brakes on and never release them. The powder coming off the brake lining stays between the brake shoes. If the brakes are released, the powder flies around the drum by centrifugal force. When the brakes are reapplied, the shoes hit the powder which then becomes a grinding compound creating heat and brake failure. The addition of rain or snow exaggerates the problem. Clean brakes are a necessity.
One solution proposed by this inventor and disclosed in his U.S. Pat. No. 4,621,715 was to provide an elongated flexible strip adapted to be wrapped around the peripheral wall of a brake drum adjacent the free interior edge thereof. A row of fins connected to the strip extended radially inwardly therefrom at a position adjacent to and interiorly of the interior edge of the brake drum to create a suction and effect a rush of air interiorly away from the brake drum both to dissipate moisture and foreign objects on the braking surface at every r.p.m. as well as to prevent the entry of moisture from the ambient atmosphere. Whereas that invention has operated successfully, it has been found that other structure can accomplish substantially the same result by blowing air interiorly across the interior surface of a brake drum rather the sucking air thereacross.
Another solution proposed by this inventor and disclosed in U.S. Pat. No. 4,674,606 was to provide a circular elongated flexible strip adapted for securement within the brake drum to create a rush of dry, cooling, cleansing air across the braking surface in response to rotation of the drum. Whereas that invention has likewise operated successfully, the inventor has developed an improved securement means for such a strip which requires no tapping of holes or other modification of the drum itself.
Whereas integral fins formed within a brake drum have been suggested as in Forbes U.S. Pat. No. 1,966,169, such fins are believed to have been impractical and/or inoperative for the reason that a dangerous grinding of metal would occur upon shifting movement of a brake shoe against the rotating fins.
A primary object of the invention therefore is to provide improved fins for cooling, drying and cleaning the brake drums of heavy-duty trucks at every r.p.m.
Another object is to provide such an apparatus for brake drums which is visually concealed and positioned so as not to interfere with inspection of or access to the brakes of a truck.
Another object is to provide such an apparatus readily suited for use with single or multiple axle vehicles and trailers.
Another object is to provide a circular strip having coolng, drying and cleaning fins formed thereon, which strip may be readily installed on conventional brake drums without modification of the drum itself.
Another object is to provide a brake drum having cooling, drying and cleaning fins integrally formed therein which are of a shape and position to cause a rush of air across the braking surface of the drum yet which are protected from engagement with a laterally shifting brake shoe within the drum.
Finally, an object is to provide an apparatus including such cooling, drying and cleaning fins, which apparatus is economical to manufacture, easy to install and efficient in operation.